Ohio Assessment for Educators (OAE) Integrated Science (024) Practice Exam

What does the law of partial pressures explain?

1. Interactions within living cells

2. Behavior of gases in mixtures

3. Distribution of electrons in an atom

4. Natural selection in species

The correct answer is: Behavior of gases in mixtures

The law of partial pressures, also known as Dalton's Law, specifically addresses the behavior of gases in a mixture. This law states that the total pressure exerted by a mixture of non-reacting gases is equal to the sum of the partial pressures of each individual gas. Each gas in the mixture behaves independently, contributing to the total pressure based on its own concentration and temperature. This concept is vital in fields such as chemistry and physics, especially when analyzing gas mixtures, calculating the partial pressure of gases, and understanding phenomena such as gas diffusion and effusion. For example, in a mixture of nitrogen and oxygen, the total pressure is the direct result of the individual pressures exerted by nitrogen and oxygen separately. The other options involve concepts that do not relate to the behavior of gases. Interactions within living cells, the distribution of electrons in an atom, and natural selection in species pertain to biology and physics areas outside of gas behavior. Thus, the correct focus of the law of partial pressures is clearly on the behavior of gases in mixtures, making that choice the accurate selection.